1. Field of the Invention
This invention relates to automotive rear windows, in general, and to multi-segment automotive windows typically located behind the seats of a pick-up truck, in particular.
2. Description of the Related Art
As is well known and understood, pick-up trucks, unlike passenger cars, are designed with an openable rear window to permit better visibility and air flow--and an ability to communicate with persons at the rear of the truck or inside a shell mounted on the truck bed. Typically, the configuration of such a rear window is a single panel which opens in a vertical plane, a three section panel which the center panel is movable in a horizontal plane, or a four section panel in which the two center panels can be slid horizontally apart in opposite directions. Several problems arise when using each of these kinds of windows due, in part, to the aerodynamic issues raised by having a flat aspect to the vehicle's cab--more specifically, noise,the buffeting of air and airborne particulate into the cab, intrusion of inclimate weather, and safety risk to the passengers inside.
For example, in the three and four section window arrangement where the center panels slide horizontally, an opening is immediately created which extends some twelve (12) to eighteen (18) inches between the roof of the cab and the top of the rear seat. Passengers located near this opening--no matter how small the opening is--are thus subjected to the direct flow of wind gusts, smoke, dust, and rain onto the top and back of their heads, neck and shoulders. As the window opening is widened, the center passenger seat often becomes unusable or unbearable at the very least. In addition, the center passenger seat usually does not have a headrest, thereby exposing the center seat passenger to serious injury if his or her head contacts the hard vertical edge of the metal frame defining the open window. This is especially the case with the multi-segment windows of those vehicles used in rough, off-road situations which bounce the passengers about, inside the vehicle.
Various power controlled multi-segment window designs which move in a horizontal plane have been disclosed in patents such as U.S. Pat. No. 4,671,013/Friese; U.S. Pat. No. 4,920,698/Friese; U.S. Pat. No. 5,146,712/Hlavaty; U.S. Pat. No. 5,613,323/Buening; and U.S. Pat. No. 5,669,181/Kollar. In a single panel window which opens in a vertical plane (e.g. U.S. Pat. No. 4,119,341/Cook),--the costs are great--due to the inclusion of a large, optically distortion-free piece of glass, heavy duty tracks, weatherstripping, and large lift motors. When a window is segmented, on the other hand, each piece can be thinner, and lighter, and less likely to contain distortions. Additionally, when a user wants to operate a single panel window, it is an all, or nothing choice, with all seating positions being then subjected to the exposure to the outside elements created by the opening. If an operator, for example, desires to have an object--such as a long pole or a piece of lumber--extend into the cab from the outside, the entire rear window would have to be lowered, leaving absolutely no protection to the occupants to the outside elements. Having the entire window lowered will also be seen to affect the stability of the vehicle at highway speeds, as wind then buffets through the vehicle.